Susan cannot have birthed a child in November of 1938, then another, just six months later, in May of 1839.  Someone's birthdate has to be wrong, or one of them isn't her child.  Based on the 1850 census and the spacing with their siblings, it's most likely that Mary's birthyear is the wrong one and that she was born in 1840, not 1839.

Susan would have been age 46, nearly 47, when George was born.  This is an extraordinary age for any woman to be having a child.  Are the younger children really hers?

1.  Marriage Record:

2.  1850 Census Every-Name-Index/Images (online at Ancestry.com, Image #106 of 145):  Gaston Co., NC, Roll M432_630, p. 444A, 792/792, enumerated 2 Nov 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

Michael Beam	33	M		Farmer		No Ca
Susan	33	F				"
John T	13	M				"
Henry E?	12	M				"
Mary A	10	F				"
Michael L	8	M				"
David L	6	M				"
Susan J	4	F				"
Sarah A	2	M				"
Mary E Shires	16	F				"

If Henry was born in November and is 12 years old here, then his birthyear should be 1837, not 1838.  If Mary was born in May and is 10 years old here, then her birthyear should be 1840, not 1839.

3.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).